Use of REFERENCE in an INTERFACE block

[AndrewC]

I feel completely clueless here but I keep getting a syntax error when trying to define access to a C function that takes a variable by reference. What am I missing?
Not an attribute-spec keyword [REFERENCE]


INTEGER*4 FUNCTION TEST
INTERFACE
INTEGER*4 FUNCTION C_TEST(a,b) BIND(C, NAME="_ctest")
INTEGER*4 , REFERENCE :: a
INTEGER*4 , REFERENCE :: b
END FUNCTION C_TEST
END INTERFACE
INTEGER*4 I,J
I=1
J=2
TEST = C_TEST(I,J)
RETURN
END

INTEGER*4 FUNCTION TEST2
INTERFACE
INTEGER*4 FUNCTION C_TEST2(a,b) BIND(C, NAME="_ctest2")
INTEGER*4 , VALUE :: a
INTEGER*4 , VALUE :: b
END FUNCTION C_TEST2
END INTERFACE
INTEGER*4 I,J
I=1
J=2
TEST2 = C_TEST2(I,J)
RETURN
END

[Steven_L_Intel1]

REFERENCE is not a Fortran language attribute. VALUE is. You do not need a REFERENCE attribute - arguments are passed by reference unless you say VALUE.

Note that this is different behavior from using the !DEC$ ATTRIBIUTES directive to specify the C calling mechanism, where the default mechanism (in most but not all cases) changes to "value" and a REFERENCE keyword is supported.

You should remove the REFERENCE keyword and also the leading underscore in the NAME= specifier, as the compiler will apply the same default decoration as the C compiler would. (Certain 10.1 compilers got this wrong, but it's been fixed for several months now.)

[AndrewC]

Thanks! I knew it had to be something obvious.
I was confused by the various 'references' to the word REFERENCE and VALUE in the help and the use in the DEC$ statement.